E-fuses may be utilized to repair integrated circuits after fabrication. E-fuses are generally preferred to laser fuses because e-fuses can be placed anywhere under the metal structure of a chip, thus potentially allowing for thousands of e-fuses to be used in a single chip. E-fuses are typically designed to break when a large electrical current passes through the e-fuses. By “blowing” these e-fuses during testing, technicians can monitor and adjust their functions to improve their quality, performance and power consumption without much human intervention.
However, e-fuses are susceptible to false programming due to electric overstress. Because the physical structure of an e-fuse is very small and fragile, a typical resistance may be about 100 ohms, and devices with such small resistance are sensitive to electrical static discharge and floating supply voltage that can reside inside an integrated circuit. Both electrical static discharge and floating supply voltage can potentially cause these electrical fuses to accidentally program themselves while in the manufacturing stage, system qualification phase, or during physical contact. Therefore, it is desirable in the art of e-fuse design to provide improved electric overstress protection, thereby increasing reliability and production yield.
In view of the foregoing, it is desirable to provide an e-fuse cell with protection from electric overstress. Furthermore, it is also desirable to provide a method for protecting an e-fuse that is cost effective and compatible with logic processing. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background.